1. Field of Invention
This invention pertains generally to the distillation of water and other liquids and, more particularly, to a distillation system and method utilizing vapor compression.
2. Related Art
U.S. Pat. Nos. 4,671,856, 4,769,113 and 4,869,067 describe a vapor compression distillation system and method in which a feed liquid enters a plate-type heat exchanger where it is preheated by heat transfer from an outgoing distilled product and waste in a three fluid, fluid-to-fluid heat transfer process. The preheated feed liquid is degassed and fed to a plate-type evaporator/condenser which has counter-flow evaporating and condensing chambers formed alternately between stacked metal plates which are separated by gaskets. Impure feed liquid enters the evaporating chambers where it boils. Heated vapor leaving the evaporating chambers passes through a mesh that removes mist, and is then pressurized by a low pressure compressor. The pressurized vapor is delivered to the condenser chambers, where it condenses as the distilled product, giving up heat to the feed liquid in the boiling chambers, and is then discharged from the system. Unvaporized feed liquid containing dissolved solids is likewise collected and discharged from the system. The liquids and vapors pass into and out of the evaporating and condensing chambers through internal manifolding consisting of openings in the plates and gaskets to provide communication between the proper manifolds and chambers.
A somewhat similar system is described in U.S. Pat. No. 5,597,453 the disclosure of which is incorporated herein by reference. That system, however, differs from the one shown in the earlier patents in that the internal manifolding has been replaced with external manifolds which are mounted adjacent to the edges of the evaporator/condenser plates and communicate with the chambers through gaps in the gaskets along the edges of the plates.